I found a cool drawing on here the other day and compared the chix to the drawing and couldn't figure out the sex. How did you know they were all pullets? I want to know this stuff, but I'm a total noob.

They lack the curved sickle feathers, lack pointed hackle and saddle feathers, lack any spur development (males and females can have spurs) but have distinct reddening and growth of the wattles and comb.

They look as though they are either laying or are getting ready to lay very soon!

The white wyandottes are cool, I like! Oh and to tell the difference between Australorps and giants, both have dark shanks, but the undersides of the feet will be white or yellow respectively. Also the giants usually have more tiny feathers on their faces, looks like stubble.
Nice birdies!